package com.mcr.reggie.controller;
import com.mcr.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;
/**
 * 文件上传与下载
 */
@Slf4j
@RestController
@RequestMapping("/common")
public class CommonController {
    @Value("${reggie.path}")
    private String BasePath;//自定义路径类
    /**
     *文件上传
     */
    @PostMapping(value = "/upload")
    public R<String> upload(MultipartFile file){
        //参数名必须和前端上传的name属性值一致
        log.info("上传文件信息"+file.toString());
        String filename = file.getOriginalFilename();
        String suffix = filename.substring(filename.lastIndexOf("."));
        filename=UUID.randomUUID().toString()+suffix;
        File dir=new File(BasePath);
        if(!dir.exists()){
            dir.mkdir();
        }
        try {
            file.transferTo(new File(BasePath+filename));
        } catch (IOException ioException) {
            ioException.printStackTrace();
        }
        return R.success(filename);
    }
    /*文件下载
     */
    @GetMapping(value = "/download")
    public void download(String name, HttpServletResponse response){
        try {
            //输入流，通过输入流读取文件内容
            FileInputStream fileInputStream=new FileInputStream(new File(BasePath+name));
            //输出流，通过输出流将文件写回浏览器，在浏览器展示图片
            ServletOutputStream outputStream = response.getOutputStream();
            response.setContentType("image/jpeg");
            //response.setContentType(xxx)作用是使客户端浏览器，区分不同种类的数据，
            //并根据不同的种类调用浏览器内不同的程序嵌入模块来处理相应的数据。
            int len=0;
            byte[] bytes=new byte[1024];
            while ((len=fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
